JP2015207362A - Manufacturing method for power storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a power storage device in which a plurality of power storage cells are connected, the method being able to easily manufacture a power storage device that restricts decrease in cell performance.SOLUTION: A manufacturing method for a power storage device, according to the invention, is a manufacturing method for a power storage device (1) in which a plurality of power storage cells (10) are connected in series, each power storage cell (10) having a first electrode (17) and a second electrode (18) projecting in opposite directions. The manufacturing method comprises the steps of: holding the plurality of power storage cells with a space between adjacent power storage cells and in a laminated state in which the first electrode alternates with the second electrode, and bringing the first electrode into contact with the second electrode of another power storage cell while extending in the direction of the lamination; joining the first and second electrodes disposed in contact with each other; and compressing the power storage cells in the laminated state, in the direction of the lamination so as to narrow the spaces.

Description

  The present invention relates to a method for manufacturing an electricity storage device, and more particularly to an electricity storage device in which a plurality of electricity storage cells are connected in series.

  With the widespread use of electronic devices such as notebook computers, mobile phones, and digital cameras, the demand for secondary batteries for driving these electronic devices is increasing. And since these electronic devices can be increased in capacity, the use of nonaqueous electrolyte secondary batteries (particularly lithium ion secondary batteries) is being promoted.

  And this non-aqueous electrolyte secondary battery is also considered for application to uses requiring high power such as vehicles (EV, HV, PHV) and household power supplies (HEMS). In this case, high power can be obtained as an assembled battery by combining the battery cells of the nonaqueous electrolyte secondary battery.

  The assembled battery is formed by connecting a predetermined number of flat batteries (unit cells) constituting battery cells in series. A flat battery forming an assembled battery is generally formed so that a power storage element (electrode body) is accommodated in a case (laminate outer package) and a pair of electrodes (electrode tabs) protrude through the case. ing. And an assembled battery is formed by connecting electrodes in series.

  An assembled battery is described in Patent Document 1, for example. Patent Document 1 describes a technique in which electrode tab joints for connecting in series the batteries that form a set when all batteries (unit cells) are stacked are provided at a plurality of positions of the assembled battery. Has been.

JP 2006-196428 A

  However, in the assembled battery of Patent Document 1, the number of connected batteries (electrode tabs) can be increased by making the positions (shapes) of the electrode tabs different. That is, as the number of batteries to be connected increases, it is necessary to manufacture unit cells having different electrode tab positions, leading to an increase in manufacturing cost.

  In addition, if the number of connected batteries increases too much, there is a problem that sufficient space for bonding is insufficient (a space for surrounding jigs during bonding processing and a reduction in the bonding area of the electrode tabs). It was.

  Furthermore, as the number of connected batteries increases, the positions of the electrode tabs differ, and the distance between the storage element (electrode body) and the electrode tab becomes non-uniform, resulting in variations in the battery performance of the unit cells. There was a problem that came to occur.

  In addition, the batteries to be connected are arranged side by side on a mounting table or the like, the electrode tabs are joined, and the joined battery assembly is folded to form an assembled battery. In this case, if the number of single cells is too large, the length in the state of being placed on the mounting table becomes long, and not only a large space is required, but also misalignment is likely to occur during joining processing. Furthermore, there is a problem that the battery assembly needs to be folded back, and the number of steps for that purpose increases.

  The present invention has been made in view of the above circumstances, and in an assembled battery (electric storage device) formed by connecting a plurality of single cells (electric storage cells), an assembled battery (electric storage device) in which deterioration in battery performance is suppressed is provided. It is an object of the present invention to provide a manufacturing method that can be easily manufactured.

  In order to solve the above-mentioned problems, the present inventor has studied the joining mode for joining a plurality of single cells (storage cells), and as a result, has reached the present invention.

  The method for manufacturing an electricity storage device of the present invention includes an electricity storage element, a case for housing the electricity storage element, a first electrode that penetrates the case while being electrically connected to the electricity storage element, and an electrical connection to the electricity storage element And a second electrode projecting in the opposite direction to the first electrode, and a method of manufacturing an electricity storage device comprising a plurality of electricity storage cells connected in series, In the stacked state in which the second electrodes are alternately positioned, the plurality of storage cells are held in a state of being spaced apart from each other, and the second electrode of another storage cell is extended with the first electrode extending in the stacking direction. A step of bringing the first electrode and the second electrode into contact with each other, and a step of compressing the stacked storage cells in the stacking direction so as to narrow the interval. It is characterized by.

  In the method for manufacturing an electricity storage device of the present invention, the electrodes are joined in a state where the interval between the electricity storage cells is widened. That is, a space for a jig for processing can be secured at the time of joining. Then, in the subsequent steps, by narrowing the interval between the storage cells, the overall size of the storage cell joined body (storage device) can be reduced. That is, in the manufacturing method of the present invention, an electricity storage device having a small overall physique (high energy density) can be easily manufactured.

  In the manufacturing method of the present invention, since the storage cells are stacked when the electrodes are joined, it is not necessary to arrange the storage cells side by side. That is, the effect that the space required for the storage cell can be reduced is exhibited.

  In addition, when welding in a state where the storage cells are arranged, a process such as folding of the storage cells after joining is necessary, but since the storage cells are joined in a stacked state, such a process is not necessary. ing. That is, the effect of reducing the number of steps required for manufacturing is exhibited.

  Furthermore, in the manufacturing method of this invention, it is not necessary to make the shape of an electrode different for every electrical storage cell. That is, it is not necessary to have a different shape depending on the arrangement position when the power storage device is manufactured, and as a result, an increase in cost can be suppressed.

It is the figure which showed the single cell of the 1st form. It is sectional drawing which showed the structure of the cell of 1st form. It is a figure which shows the state which has arrange | positioned the cell which forms an assembled battery with a 1st form. It is a figure which shows the state which joins the cell which forms an assembled battery with a 1st form. It is a figure which shows the state which compressed the cell in order to form an assembled battery with a 1st form. It is a figure which shows the shape of the positive electrode tab of a 2nd form. It is a figure which shows the external shape of the cell of a 3rd form. It is a figure which shows 1 process at the time of the assembly of a 4th form. It is a figure which shows 1 process at the time of the assembly of a 4th form. It is a figure which shows the process at the time of the assembly of a 5th form. It is a figure which shows the guide jig at the time of the compression in a 6th form.

Hereinafter, the present invention will be described using embodiments.
As an embodiment of the present invention, an assembled battery of a non-aqueous electrolyte secondary battery was manufactured.

[First form]
In this embodiment, the assembled battery 1 in which a plurality of nonaqueous electrolyte secondary batteries are connected in series was manufactured by the manufacturing method shown in FIGS.
(Unit cell structure)
First, the unit cell 10 of the nonaqueous electrolyte secondary battery shown in FIG. 1 was prepared. The unit cell 10 corresponds to a storage cell.

As shown in FIG. 2, the unit cell 10 includes an electrode body 15 in which a plurality of layers of a positive electrode 11 and a negative electrode 12 are stacked via a separator 13 and is enclosed (accommodated) together with a nonaqueous electrolyte 14. Yes. A positive electrode tab 17 that penetrates the battery case 16 is electrically connected to the positive electrode 11, and a negative electrode tab 18 that penetrates the battery case 16 is electrically connected to the negative electrode 12. The positive electrode tab 17 and the negative electrode tab 18 are provided so as to extend in directions opposite to each other (opposite directions). The two electrode tabs 17 and 18 are both made of a metal foil (metal sheet), and are provided at the center of the unit cell 10 in the width direction. The electrode body 15 and the nonaqueous electrolyte 14 of the unit cell 10 correspond to a power storage element. The positive electrode tab 17 corresponds to the first electrode. The negative electrode tab 18 corresponds to a second electrode.
As shown in FIGS. 1 and 2, the unit cell 10 is formed so as to protrude from the surface formed by the pair of electrode tabs 17 and 18 to one side in the thickness direction (electrode stacking direction).

  The portion of the negative electrode tab 18 that protrudes from the battery case 16 becomes a connection portion 180 that is joined to the positive electrode tab 17 of another unit cell 10. The protruding length of the connecting portion 180 from the battery case 16 is a length that can be connected to the positive electrode tab 17 of another unit cell 10.

  The positive electrode tab 17 protrudes from the battery case 16 with a base 170 having the same length as the connecting portion 180 of the negative electrode tab 18, an expansion / contraction part 171 provided in the protruding tip direction of the base 170, and a protrusion of the expansion / contraction part 171. And a connection part 172 connected to the connection part 180 of the negative electrode tab 18 of another unit cell 10 provided in the distal direction. The base 170 and the connecting portion 172 have a flat plate shape, and the stretchable portion 171 has a bellows shape in which the positive electrode tab 17 is folded back at least once. The expansion / contraction part 171 formed in the bellows shape of the positive electrode tab 17 corresponds to a folded part.

  The expansion / contraction part 171 has a bellows shape in which the positive electrode tab 17 is folded once or more, and allows the relative position of the base part 170 and the connection part 172 to be changed by buffering the bellows shape (a change in distance can be buffered). Formed). The bellows shape of the expansion / contraction part 171 not only allows (buffers) a change in the distance in the stacking direction of the base 170 and the connection part 172 but also allows (buffers) a change in the extending direction of the base 170. The bellows shape of the stretchable portion 171 that allows the relative position to change is preferably a shape in which the portion connected to the base portion 170 and the connection portion 172 collapses toward the electrode body 15. In this embodiment, the positive electrode tab 17 is substantially the same. It is folded back to make an M-shaped cross section. The bellows-shaped positive electrode tab 17 may be formed by bending the flat plate-shaped positive electrode tab 17 after the unit cell 10 is assembled, or by assembling the unit cell 10 using the bent positive electrode tab 17. Any of them may be used.

(Manufacture of assembled batteries)
A predetermined number of unit cells 10 shown in FIGS. In this embodiment, as shown in FIG. 3, four (plural) pieces were prepared.

(Single cell arrangement)
The unit cell 10A to 10D is held in a stacked state in which the two electrode tabs 17 and 18 are alternately positioned and spaced apart from each other. At this time, the positive electrode tab 17A of the unit cell 10A comes into contact with the connection unit 180B of the negative electrode tab 18B of another unit cell 10B in which the connection unit 172A is stacked. At this time, it is good also as a fixed state with a jig | tool so that the state which two connection part 172A, 180B contact | abutted can be hold | maintained. This jig may be a processing jig (horn 20, anvil 21) used in a process described later.

In a state where the cells 10A and 10B are held, the stretchable portion 171A is in a state where the bellows is extended.
Similar to the relationship between the two unit cells 10A and 10B, as shown in FIG. 3, four unit cells 10A to 10D are arranged.

  As shown in FIG. 3, in a state where the four unit cells 10 </ b> A to 10 </ b> D are arranged, the stretchable portion 171 is not in a state in which the bellows shape extends completely to form a flat plate, but in a state in which the bellows shape remains slightly. Preferably there is.

(Joining)
The contact portions of the connection portions 172A and 180B of the two unit cells 10A and 10B are joined. As shown in FIG. 4, the joining is ultrasonic welding in which the horn 20 and the anvil 21 are welded by applying ultrasonic vibration while pressing the two connecting portions 172 </ b> A and 180 </ b> B in the thickness direction. In addition, the horn 20 and the anvil 21 move in a direction perpendicular to the paper surface of FIG. The horn 20 and the anvil 21 may be inserted from the same direction or from different directions.
As a result, the positive electrode tab 17A and the negative electrode tab 18B of the two unit cells 10A and 10B were joined. Two unit cells 10A and 10B were joined in series.

  Similarly, the unit cells 10B to 10D are joined. In addition, in FIG. 4, the horn 20 and the anvil 21 for welding the single cells 10B to 10D are indicated by broken lines. Four unit cells 10A to 10D were joined in series.

(compression)
The horn 20 and the anvil 21 are removed from the processing position.
As shown in FIG. 5, the four unit cells 10 </ b> A to 10 </ b> D that are in a stacked state at intervals are compressed and contacted in the stacking direction (the arrow direction in FIG. 5). At the same time, the expansion / contraction part 171 of the positive electrode tab 17 is also compressed in the contracting direction (the same direction as the arrow direction in FIG. 5).
As a result, the assembled battery 1 of this embodiment was manufactured.

  In this embodiment, the connection parts 172A and 180B are joined in a state where the four unit cells 10A to 10D to be joined are arranged at intervals, and then compressed in the stacking direction to produce the assembled battery 1. Is done. That is, since the electrode tabs 17 and 18 are joined in a state in which the unit cells 10A to 10D are laminated in advance, it is not necessary to perform processing such as turning back the electrode tabs 17 and 18 after joining.

  Since the electrode tabs 17 and 18 are joined in a state in which the unit cells 10A to 10D are stacked in advance, the unit cells 10A to 10D are used in comparison with the case where the unit cells 10A to 10D are arranged in a long shape. The required space can be greatly reduced.

At the time of joining processing, the unit cells 10A to 10D to be joined are held in a stacked state at intervals, and a processing jig (horn 20, anvil 21) can be arranged at the joining portion.
A compact assembled battery 1 can be manufactured by taking out the processing jig (horn 20, anvil 21) after joining and then compressing it.
In this embodiment, the unit cell 10 constituting the assembled battery 1 has the same shape, so that an increase in cost required for manufacturing the unit cell 10 can be suppressed.

  Joining can be performed over the entire length of the electrode tabs 17 and 18 in the width direction (direction perpendicular to the protruding direction), and the area of the joined portions can be secured widely. That is, the electrode tabs 17 and 18 can be firmly joined.

Furthermore, in this embodiment, since the joining process is performed in a state in which the stretchable part 171 has a slight bellows shape, the stretchable part 171 can buffer vibration during the joining process. That is, the electrode tabs 17 and 18 can be joined without causing damage.
[Second form]
This form is the same form as the first form except that the shape of the stretchable part 171 of the unit cell 10 is different.

As shown in FIG. 6, the stretchable part 171 of this embodiment is formed in a bellows shape with an increased number of turns. Similarly to the first embodiment, the shape of the stretchable portion 171 of this embodiment does not protrude from the distal end portion of the base portion 170 (the portion where the base portion 170 and the stretchable portion 171 are connected) even when the assembled battery is formed and compressed.
Even in this embodiment, by adjusting the shape of the stretchable portion 171, the small assembled battery 1 can be manufactured even if the number of times of folding is increased.

[Third embodiment]
This embodiment is the same as the first embodiment except that the direction in which the unit cell 10 is convex is different.
As shown in FIG. 7, the unit cell 10 is formed so as to protrude in both the thickness direction (electrode stacking direction) from the surface formed by the pair of electrode tabs 17 and 18.
Even in this embodiment, the same effect as in the first embodiment can be exhibited.

  As a modified form of the third form, there is a form in which the positive electrode tab 17 is convex in the direction opposite to the direction in which the positive electrode tab 17 is folded back. However, in this case as well, the same as the first form and the third form The effect of can be demonstrated.

[Fourth form]
As shown in FIGS. 8A to 8B, this embodiment is the same as the first embodiment except that the cells are arranged and joined one by one.

In this embodiment, the unit cell 10A and the unit cell 10B are joined (FIG. 8 (a)), and then the unit cell 10C is arranged, and the connecting portion 172B of the positive electrode tab 17B of the unit cell 10B and the negative electrode tab 18C of the unit cell 10C. The connecting portion 180C is joined (FIG. 8B).
Then, similarly, the unit cell 10C and the unit cell 10D are joined.

  In this embodiment, each time the joining process is performed, the unit cell 10 is arranged, so that no other unit cell exists near the horn 20. That is, the space of the horn 20 for processing can be ensured more and joining can be performed more reliably.

[Fifth form]
This form is the same form as the first form except that the cells are joined simultaneously.
In this embodiment, as shown in FIG. 9, a plurality of joints can be joined at a time, so that joining can be performed faster.

[Sixth form]
This embodiment is the same as the first embodiment except that when the cells are compressed after the cells 10 are joined, the bending of the electrode tab 17 is guided by the guide jig 3 (30, 31). is there.

In this embodiment, as shown in FIG. 10, when the unit cell 10 is compressed, the bellows-shaped valley portion of the expansion / contraction part 171 is guided by the guide jig 3 (30) in the depth direction of the valley (thick arrow in the figure). Press on. The guide jig 3 (30) is removed from the assembled battery 1 after compression.
Accordingly, the bellows shape can be reliably compressed in the direction in which the bellows is contracted without causing the expansion / contraction part 171 to be twisted or the like.
At this time, by disposing the guide jig 31 indicated by the broken line in FIG. 10, the expansion / contraction part 171 can be compressed more reliably.

[Seventh form]
This form is the same form as the first form except that when the single cells 10A to 10D are arranged for bonding, the single cells 10A to 10D are inclined.

  In this embodiment, when the unit cells 10A to 10D are held in a state of being spaced apart from each other, the unit cells 10A to 10D are arranged along a direction intersecting each other so as to form a bellows shape. Has been.

  In the first embodiment, as shown in FIGS. 3 to 4, the unit cells 10 </ b> A to 10 </ b> D are arranged in parallel. On the other hand, in this embodiment, the unit cells 10A to 10D are arranged along the direction in which the unit cells 10A to 10D alternately intersect so that the unit cells 10A to 10D form a bellows shape.

In this embodiment, the expansion / contraction part 171 not only buffers the interval in the stacking direction, but also allows a change in the angle formed by the cells 10A to 10D. The stretchable part 171 preferably has an acute angle formed by the base 170 and the connecting part 172.
In this embodiment, a larger space between the two unit cells 10, 10 can be secured. That is, the workability of joining (movability of the horn 20 and the anvil 21) is improved.

[Eighth form]
This embodiment is the same as the first embodiment except that the method of joining the electrode tabs 17 and 18 of the unit cell 10 is different.

In the first embodiment, the electrode tabs 17 and 18 are joined by ultrasonic welding, but a joining method other than ultrasonic welding can be employed. Other joining methods include friction stir welding and resistance welding.
Also in this embodiment, the electrode tabs 17 and 18 can be joined as in the first embodiment.

[Nonaqueous electrolyte secondary battery]
The type of the non-aqueous electrolyte secondary battery forming the unit cell is not limited, but is preferably a lithium ion secondary battery in which lithium ions are occluded and released by both positive and negative electrodes.

(Positive electrode)
In the positive electrode 11, a positive electrode mixture obtained by mixing a positive electrode active material, a conductive material, and a binder is applied to a positive electrode current collector to form a positive electrode mixture layer.

  A conventionally known positive electrode active material can be used as the positive electrode active material. As the positive electrode active material, for example, various oxides, sulfides, lithium-containing oxides, conductive polymers, and the like can be used. The positive electrode active material is preferably a lithium-transition metal composite oxide.

Lithium - transition metal composite oxide is preferably a lithium metal compound polyanion structure ^{_{(Li α M 0 β X η}} O 4-γ Z γ). (Note that M ⁰ : one or more selected from Mn, Co, Ni, Fe, Cu, Cr, Mg, Ca, Zn, Ti, one or more selected from X: P, As, Si, Mo, Ge, Z: One or more selected from Al, Mg, Ca, Zn and Ti can be optionally contained, 0 ≦ α ≦ 2.0, 0 ≦ β ≦ 1.5, 1 ≦ η ≦ 1.5, 0 ≦ γ ≦ 1.5)

The lithium-transition metal composite oxide is preferably a lithium-transition metal composite oxide having an olivine structure. Examples of the olivine-structured lithium-transition metal composite oxide include LiFePO ₄ and LiFe _x Mn _1-x PO ₄ (0 ≦ x <1).

  The conductive material ensures the electrical conductivity of the positive electrode 11. Examples of the conductive material include, but are not limited to, graphite fine particles, acetylene black, ketjen black, carbon black such as carbon nanofiber, and amorphous carbon fine particles such as needle coke.

  The binder binds the positive electrode active material particles and the conductive material. As the binder, for example, PVDF, EPDM, SBR, NBR, fluororubber, and the like can be used, but are not limited thereto.

  The positive electrode mixture is dispersed in a solvent and applied to the positive electrode current collector. As the solvent, an organic solvent that normally dissolves the binder is used. Examples thereof include, but are not limited to, NMP, dimethylformamide, dimethylacetamide, methyl ethyl ketone, cyclohexanone, methyl acetate, methyl acrylate, diethyltriamine, NN-dimethylaminopropylamine, ethylene oxide, and tetrahydrofuran. In some cases, a positive electrode active material is slurried with PTFE or the like by adding a dispersant, a thickener, or the like to water.

  As the positive electrode current collector, for example, a material obtained by processing a metal such as aluminum or stainless steel, for example, a foil processed into a plate shape, a net, a punched metal, a foam metal, or the like can be used, but is not limited thereto.

(Negative electrode)
In the negative electrode 12, a negative electrode mixture obtained by mixing a negative electrode active material and a binder is applied to the surface of the negative electrode current collector to form a negative electrode mixture layer.

  As the negative electrode active material, a conventional negative electrode active material can be used. A negative electrode active material containing at least one element of Sn, Si, Sb, Ge, and C can be given. Among these negative electrode active materials, C is preferably a carbon material capable of occluding and desorbing electrolyte ions of a lithium ion secondary battery (having Li storage ability), and more preferably amorphous coated natural graphite. preferable.

  Of these negative electrode active materials, Sn, Sb, and Ge are alloy materials that have a large volume change. These negative electrode active materials may form an alloy with another metal such as Ti—Si, Ag—Sn, Sn—Sb, Ag—Ge, Cu—Sn, and Ni—Sn.

  As the conductive material, a carbon material, metal powder, conductive polymer, or the like can be used. From the viewpoint of conductivity and stability, it is preferable to use a carbon material such as acetylene black, ketjen black, or carbon black.

As the binder, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), fluororesin copolymer (tetrafluoroethylene / hexafluoropropylene copolymer) SBR, acrylic rubber, fluororubber, Examples thereof include polyvinyl alcohol (PVA), styrene / maleic acid resin, polyacrylate, and carboxymethyl cellulose (CMC).
Examples of the solvent include organic solvents such as N-methyl-2-pyrrolidone (NMP) or water.

  As the negative electrode current collector, a conventional current collector can be used, which is obtained by processing a metal such as copper, stainless steel, titanium, or nickel, such as a foil processed in a plate shape, a net, a punched metal, a foam metal, etc. However, it is not limited to these.

(Nonaqueous electrolyte)
The non-aqueous electrolyte 14 is formed by dissolving a supporting salt in an organic solvent.
The supporting salt of the non-aqueous electrolyte 14 is not particularly limited in kind, but an inorganic salt selected from LiPF ₆ , LiBF ₄ , LiClO ₄ and LiAsF ₆ , derivatives of these inorganic salts, LiSO ₃ CF ₃ , Organic salt selected from LiC (SO ₃ CF ₃ ) ₃ and LiN (SO ₂ CF ₃ ) ₂ , LiN (SO ₂ C ₂ F ₅ ) ₂ , LiN (SO ₂ CF ₃ ) (SO ₂ C ₄ F ₉ ) And at least one of these organic salt derivatives. These supporting salts can further improve the battery performance, and can maintain the battery performance higher even in a temperature range other than room temperature. The concentration of the supporting salt is not particularly limited, and it is preferable to appropriately select the supporting salt and the organic solvent in consideration of the use.

The organic solvent (non-aqueous solvent) in which the supporting salt dissolves is not particularly limited as long as it is an organic solvent used in ordinary non-aqueous electrolytes. For example, carbonates, halogenated hydrocarbons, ethers, ketones, Nitriles, lactones, oxolane compounds and the like can be used. In particular, propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, vinylene carbonate and the like, and mixed solvents thereof are suitable. Among these organic solvents mentioned in the examples, in particular, by using one or more non-aqueous solvents selected from the group consisting of carbonates and ethers, the solubility of the supporting salt, the dielectric constant and the viscosity are excellent, and the battery The charge / discharge efficiency is preferable.
In the lithium ion secondary battery, the most preferable nonaqueous electrolyte 14 is one in which the supporting salt is dissolved in an organic solvent.

(Separator)
The separator 13 interposed between the positive electrode mixture layer and the negative electrode mixture layer electrically insulates the positive electrode mixture layer and the negative electrode mixture layer and holds the nonaqueous electrolyte 14. As the separator 13, for example, a porous synthetic resin film, particularly a porous film of polyolefin polymer (polyethylene, polypropylene) is used. The separator 13 is formed with a size larger than that of the mixture layer in order to ensure electrical insulation between the two mixture layers.

(Battery case)
The battery case 16 is formed from a laminate outer package. The laminate exterior body is composed of a laminate film. The laminate film includes a plastic resin layer 160 / metal foil 161 / plastic resin layer 162 in this order. In addition to these layers 160, 161, 162, a resin layer or a metal layer may be included. Some surface treatment (plasma treatment, acid treatment, chemical treatment, etc.) is performed between the surface of the laminate film and each layer, and the adhesion between each layer and the member to be adhered can be improved. A plastic resin layer is disposed on the surface to be heat-sealed. The plastic resin layers 160 and 162 are bonded by pressing against another laminate film (metal foil 161) or the like while being softened by heat or some solvent. The plastic resins constituting the two plastic resin layers 160 and 162 may be the same material or different materials. The plastic resin constituting the plastic resin layers 160 and 162 is desirably a material having high stability with respect to the non-aqueous electrolyte. For example, polyolefin such as polypropylene and polyethylene, polyester such as polyethylene terephthalate and polybutylene terephthalate, and ABS resin , Acrylic resins such as vinyl chloride resin and polymethyl methacrylate, fluororesins such as nylon and ethylene tetrafluoroethylene copolymer, polycarbonates, etc. may be used singly or in multiple layers or as a mixture (as a polymer alloy). it can. The metal foil 161 is not particularly limited, and an aluminum foil or the like can be adopted.

  The electrode tabs 17 and 18 are electrically connected to the positive and negative electrodes 11 and 12 of the electrode body 15. The electrode tabs 17 and 18 can use the same material as each collector of the positive electrode 11 and the negative electrode 12 to be connected.

  In the portion where the electrode tabs 17 and 18 pass through the battery case 16 made of the laminate exterior body, the plastic resin layer of the laminate film constituting the laminate exterior body and the electrode tabs 17 and 18 are joined so as to keep a sealed state. . That is, when the laminated films are stacked and fused, the electrode tabs 17 and 18 and the laminated film are joined by sandwiching the electrode tabs 17 and 18 therebetween.

  The electrode tabs 17 and 18 can be surface-treated for the purpose of improving the adhesiveness with the laminate film, or can be composed of a metal tab main body and a plastic resin layer covering the surface. Examples of the surface treatment performed on the electrode tabs 17 and 18 include a physical treatment that performs surface roughening and the like and expects an anchor effect, and a treatment that chemically activates the surface by plasma treatment or primer application.

  The electrode tabs 17 and 18 are not limited in width, but are preferably as wide as possible in order not to impede current flow with the electrodes 11 and 12. If the width of the electrode tabs 17 and 18 is widened, it can contribute to heat radiation of the heat generated in the electrode body 15.

  The electrode tabs 17 and 18 are preferably connected to the center of the electrodes 11 and 12 in the width direction. According to this configuration, the distance from the electrode tabs 17 and 18 to both ends in the width direction of the electrodes 11 and 12 is not biased, and a decrease in battery performance due to an increase in internal resistance can be suppressed.

[Other configuration of single cell]
In each of the above embodiments, a non-aqueous electrolyte secondary battery is used as a member corresponding to the electricity storage device of the present invention. However, if the electricity storage device of the present invention has an electricity storage element capable of storing and releasing electric energy, A specific configuration is not limited.
Examples of the electricity storage device other than the non-aqueous electrolyte secondary battery include an electric double layer capacitor.

1: assembled battery 10, 10A to 10D: single battery 11: positive electrode 12: negative electrode 13: separator 14: nonaqueous electrolyte 15: electrode body 16: battery case 160, 162: plastic resin layer 161: metal foil 17: positive electrode tab 170 : Base 171: Stretchable part 172: Connection part 18: Negative electrode tab 180: Connection part 20: Horn 21: Anvil 3, 30, 31: Guide jig

Claims (6)

A power storage element (15), a case (16) for housing the power storage element, a first electrode (17) penetrating through the case while being electrically connected to the power storage element, Storage device (1) comprising a plurality of storage cells (10) connected in series, each having a second electrode (18) protruding in the opposite direction to the first electrode in a connected state. ) Manufacturing method,
The stacked state in which the first electrode and the second electrode are alternately positioned, the plurality of storage cells are held in a state of being spaced apart from each other, and the first electrode is extended in the stacking direction Contacting a second electrode of another storage cell in a state;
Joining the abutted first electrode and the second electrode;
Compressing the stacked storage cells in the stacking direction so as to narrow the interval;
The manufacturing method of the electrical storage device characterized by having.   The method for manufacturing an electricity storage device according to claim 1, wherein the first electrode is formed so as to be able to buffer a change in distance in a stacking direction of the electricity storage cells.   The said 1st electrode is a manufacturing method of the electrical storage device of any one of Claims 1-2 which have a folding | returning part (171).   The method for manufacturing an electricity storage device according to claim 1, wherein the joining is any one of ultrasonic welding, friction stir welding, and resistance welding.   The method of manufacturing an electricity storage device according to claim 1, wherein the electricity storage element is an electrode body of a nonaqueous electrolyte secondary battery.   The method for manufacturing an electricity storage device according to claim 1, wherein the first electrode is a metal foil.

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